The main aim of the study is to evaluate substance abuse intervention give during psychiatric hospitalization to substance abusing psychiatric in -patients ("dual diagnosis patients"). Research shows that about half of psychiatric in-patients are substance abusers (1-7). Type and effectiveness of substance abuse intervention will be assessed by comparing three groups of subjects given different interventions and assessing these patients for six months after discharge. Another aim of the study is to learn more about "dual diagnosis" patients by careful assessment of psychiatric diagnosis, substance abuse, and clinical courses over time. Subjects will be assigned randomly to one of three intervention conditions: 1) A passive Advise list (Control Group); 2) A drug and alcohol Discussion Group; 3) A highly structured relapse prevention Workbook Group. Subjects will receive no further "study"intervention after discharge and will be re-assessed at 1, 3, and 6 months. Two hundred and fifty subjects will be recruited at a rate of 32 new cases in 12-week segments from the psychiatric inpatient service at University Hospital. New cases will be assessed for 2 years of the 3 - year grant period. The main benefits of this study will be to define the utility of substance abuse intervention provided during psychiatric hospitalization, an area about which virtually nothing is know. Interventions studied are those which could readily be incorporated into existing general psychiatric inpatient units could markedly affect braining of psychiatric staff cause better patient care.